bug#24109: 24.5; Long lines in message mode make Emacs irresponsive

[Dirk-Jan C. Binnema]

On Saturday Jul 30 2016, John Mastro wrote:

> Eli Zaretskii <eliz@gnu.org> wrote:
>> Btw, line 1452 in fns.c is not in assq_no_quit, not in any Emacs 24.x
>> version (the bug is reported for 24.5).  In 25.1, line 1452 is indeed
>> inside assq_no_quit, so perhaps the version and/or line numbers are
>> reported incorrectly.
>
> The apparent discrepancy is because the reporter is using 24.5 and
> reported the bug against that version, but the author/maintainer of mu4e
> reproduced the bug in 25.1 and posted the backtrace.

Indeed.

I just tried to reproduce the issue with a freshly compiled emacs from
the emacs-25 branch, to get an 'xbacktrace'. But alas, I cannot
reproduce the issue right now, nor with a slightly older emacs :-/

The special case here was a ~700 character subject-header for some spam
message. The "corruption" in the message is a bit of a misnomer, I think
-- it was just emacs scrolling all the way to the right, thus scrolling
the other messages out of view. Haven't seen that with happening with
emacs-25.

I installed emacs-24.5 as well, and cannot reproduce it there
either. So, hopefully reporter is able to reproduce it and get an
xbacktrace.